1) Transfer the beef in a pan with water. Add onion, tomatoes and gabi and simmer for about 1 1/2 hours if using an ordinary pan or for 45 minutes using a pressure cooker.
2) Once the meat is tender, add sinigang mix ( I used 1 1/2 big packets as I like it very sour). Season with salt or patis to taste. Add labanos, okra, and talong and simmer for 2 minutes.
3) Add sitaw and simmer for another 2 minutes. Lastly add kangkong and remove from the heat. Heat from the soup is enough to cook the kangkong. Ready to serve.